DE970571T1 - COMMUNICATION STATION WITH SEVERAL ANTENNAS - Google Patents

Claims (20)

InterDigital Technology Corporation 923 728.4 I 80294EP F/Kr/hm patent claims 1. A communication station for use in a CDMA communication system, comprising: an antenna system comprising: a plurality of antennas for receiving CDMA communication signals; a summer associated with the antennas and having an output for outputting a combined signal; a first of the antennas which is directly coupled to the summer;
a second of the antennas associated with a first delay unit that imparts a first fixed delay to the signals received by the second antenna; wherein the first delay unit is coupled to the summer, thereby outputting a combined signal having a known distortion corresponding to at least the first fixed delay;
a receiver coupled to the output of the summator; and
a modem for receiving an individual communications signal associated with a unique CDMA code coupled to the receiver, the modem including distortion compensation means for compensating for at least the known signal distortion. 2. Communication station according to claim 1, wherein each of the plurality of antennas, except the first antenna, is associated with a respective delay unit which is coupled to the summer and which imparts a different, fixed delay to the signal received by the respective antenna, whereby the delayed signals are combined with the signal of the first antenna by the summer, whereby the known phase distortion of the combined output signal corresponds to all of the fixed delays. 3. A communication station according to claim 2, wherein each different fixed delay results in a phase distortion of at least two chips relative to any other delay in the signal output of the summer. 4. A communications station according to claim 3, wherein the antenna system comprises three antennas, a third of the antenna being associated with a second delay unit, which imparts a second delay to the signal received by the third antenna, whereby the known phase distortion of the summer output corresponds to the predetermined delays imparted by the first and second delay units. 5. The communication station of claim 4, wherein the delay imparted by the first delay unit results in a three-chip delay and the delay imparted by the second delay unit results in a seven-chip delay. 6. A communication station according to claim 5, wherein the modem comprises a vector correlator for generating filter coefficients for an adaptive matching filter based on a signal distortion determined by the vector correlator; wherein the vector correlator has a processing capacity of at least eleven chips, whereby the vector correlator compensates for the known distortion and the multipath distortion detectable within its processing capacity; and
wherein the processing communication signals with the unique CDMA code of the adaptive matching filter use coefficients generated by the vector correlator. 7. Communication station according to claim 6, wherein the modem further comprises an automatic power control which is connected to the adaptive matching filter for generating feedback forward power control signals for transmission to the station that sent the signal processed by the modem. 8. Communication station according to claim 4, wherein the antennas are spaced apart by at least six wavelengths. 9. A communications station according to claim 4, wherein the antennas are spaced no more than three yards apart. 10. The communication station of claim 4, wherein the receiver and the modem are arranged in physically separate units, and further comprising a cable for coupling the modem to the receiver, the cable supplying power to the receiver unit. 11. The communications station of claim 10, wherein the cable is at least 20 feet long. 12. The communication station of claim 1, wherein the receiver is a physically separate unit from the modem, further comprising a cable for coupling the modem to the receiver, which includes power conductors for supplying power from the modem unit to the receiver unit. 13. The communications station of claim 12, wherein the communications station is a subscriber unit and the cable is at least 20 feet long. 14. The communication station of claim 1, wherein the modem includes a vector correlator for generating filter coefficients for an adaptive matching filter based on signal distortions determined by the vector correlator; wherein the vector correlator has a processing capacity equal to at least a predetermined chip delay corresponding to the known delay, whereby the vector correlator compensates for the known delay and the multipath delay orderable within its processing capacity; DE/EP O 970 571 Tl -4- wherein the adaptive matching filter processes individual communication signals associated with the unique CDMA code using coefficients generated by the vector correlator, thereby achieving increased signal gain to be attributed in part to compensation for the known distortion. 15. The communications station of claim 14, wherein the modem further comprises an automatic power control in conjunction with the adaptive matching filter for generating power control signals for transmission to the station that sent the signal just processed by the modem. 16. Communication station according to claim 1, further comprising: a plurality of modems coupled to the receiver, each modem receiving an individual communications signal associated with a unique CDMA code such that multiple communications received via the receiver can be processed simultaneously, each modem including distortion compensation means for compensating for at least the known signal distortion. 17. Communication station according to claim 16, wherein the communication station is a base station. 18. The communications station of claim 1, wherein the modems are coupled to the RF receiver/transmitter unit by a cable that is at least 20 feet long. 19. A communications station according to claim 18, wherein the cable supplies power to the RF receiver/transmitter unit, whereby the RF receiver/transmitter unit can be mounted near the antenna system without regard to the location of an independent power source. 20. A communication station for use in a CDMA communication system, comprising: DE / EP 0 S70571T1 -5- an antenna system comprising: first, second and third antennas for receiving CDMA communication signals; a first summer coupled to the first and second antennas and having an output for outputting a first combined signal, the first antenna being coupled to the first summer through a first delay unit; a second summer coupled to the first summer via a second delay unit and coupled to the third antenna, the second summer having an output for outputting a second combined signal; a receiver coupled to the output of the second summer; and a modem for receiving an individual communication signal associated with a unique CDMA code coupled to the receiver, the modem including phase distortion compensation means for compensating for at least the known signal distortion.